noumenal

adj

1. (especially, not-comparable)Of or pertaining to the noumenon or the realm of things as they are in themselves.

   “We may here distinguish between two kinds of reality, phenomenal or relative, and noumenal or absolute.”

   “Nor can the elements of the phenomenal world derive any complexity from the interaction of the noumenal elements which they represent with the complex structure of the precipients.”

   “When Kant says that it is impossible to know anything about, or apply any categories to, the noumenal realm, he would seem to be doing just what cannot be done.”